Preparation of polarity-marked microtubules using a plus-end capping DARPin

The eukaryotic cytoskeleton is formed in part by microtubules, which are relatively rigid filaments with inherent structural polarity. One consequence of this polarity is that the two ends of a microtubule have different properties with important consequences for their cellular roles. These differen...

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Detalhes bibliográficos
Autores: Henkin, Gil, Brito, Cláudia, Plückthun, Andreas, Surrey, Thomas
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Recursos:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10230/69511
Acesso em linha:http://hdl.handle.net/10230/69511
http://dx.doi.org/10.21769/BioProtoc.5109
Access Level:acceso abierto
Palavra-chave:DARPins
Fluorescence microscopy
In vitro reconstitution
Microtubule polarity
Microtubule-associated proteins (MAPs)
Microtubules
Molecular motors
Descrição
Resumo:The eukaryotic cytoskeleton is formed in part by microtubules, which are relatively rigid filaments with inherent structural polarity. One consequence of this polarity is that the two ends of a microtubule have different properties with important consequences for their cellular roles. These differences are often challenging to probe within the crowded environment of the cell. Fluorescence microscopy-based in vitro assays with purified proteins and stabilized microtubules have been used to characterize polarity-dependent and end-specific behaviors. These assays require ways to visualize the polarity of the microtubules, which has previously been achieved either by the addition of fluorescently tagged motor proteins with known directionality or by fluorescently polarity marking the microtubules themselves. However, classical polarity-marking protocols require a particular chemically modified tubulin and generate microtubules with chemically different plus and minus segments. These chemical differences in the segments may affect the behavior of interacting proteins of interest in an undesirable manner. We present here a new protocol that uses a previously characterized, reversibly binding microtubule plus-end capping protein, a designed ankyrin repeat protein (DARPin), to efficiently produce polarity-marked microtubules with different fluorescently labeled, but otherwise biochemically identical, plus- and minus-end segments. Key features • Produces polarity-marked microtubules with biochemically identical segments • Allows analysis of end-specific and polarity-dependent activities of purified microtubule-associated proteins • Requires purified microtubule plus-end capping DARPin (D1)2 • Concentrations optimized for porcine brain tubulin.